From f5c4671bfbad96bf346bd7e9a21fc4317b4959df Mon Sep 17 00:00:00 2001
From: Indrajith K L
Date: Sat, 3 Dec 2022 17:00:20 +0530
Subject: Adds most of the tools
---
v_windows/v/old/examples/process/.ignore | 1 +
v_windows/v/old/examples/process/command.v | 34 +++++++++
v_windows/v/old/examples/process/execve.v | 17 +++++
v_windows/v/old/examples/process/process_script.v | 59 +++++++++++++++
.../v/old/examples/process/process_stdin_trick.v | 83 ++++++++++++++++++++++
5 files changed, 194 insertions(+)
create mode 100644 v_windows/v/old/examples/process/.ignore
create mode 100644 v_windows/v/old/examples/process/command.v
create mode 100644 v_windows/v/old/examples/process/execve.v
create mode 100644 v_windows/v/old/examples/process/process_script.v
create mode 100644 v_windows/v/old/examples/process/process_stdin_trick.v
(limited to 'v_windows/v/old/examples/process')
diff --git a/v_windows/v/old/examples/process/.ignore b/v_windows/v/old/examples/process/.ignore
new file mode 100644
index 0000000..e42252a
--- /dev/null
+++ b/v_windows/v/old/examples/process/.ignore
@@ -0,0 +1 @@
+command
\ No newline at end of file
diff --git a/v_windows/v/old/examples/process/command.v b/v_windows/v/old/examples/process/command.v
new file mode 100644
index 0000000..718ce96
--- /dev/null
+++ b/v_windows/v/old/examples/process/command.v
@@ -0,0 +1,34 @@
+module main
+
+import os
+
+// basic example which shows how to use the Command function
+
+fn exec(path string) string {
+ mut out := ''
+ mut line := ''
+ mut cmd := os.Command{
+ path: path
+ }
+ cmd.start() or { panic(err) }
+
+ for {
+ line = cmd.read_line()
+ println(line)
+ out += line
+ if cmd.eof {
+ return out
+ }
+ }
+ return out
+}
+
+fn main() {
+ mut out := ''
+ exec("bash -c 'find /tmp/'")
+ out = exec('echo to stdout')
+ out = exec('echo to stderr 1>&2')
+ println("'$out'")
+ // THIS DOES NOT WORK, is error, it goes to stderror of the command I run
+ assert out == 'to stderr'
+}
diff --git a/v_windows/v/old/examples/process/execve.v b/v_windows/v/old/examples/process/execve.v
new file mode 100644
index 0000000..f840c8d
--- /dev/null
+++ b/v_windows/v/old/examples/process/execve.v
@@ -0,0 +1,17 @@
+module main
+
+import os
+
+fn exec(args []string) {
+ os.execve('/bin/bash', args, []) or {
+ // eprintln(err)
+ panic(err)
+ }
+}
+
+fn main() {
+ // exec(["-c","find /"]) //works
+ exec(['-c', 'find /tmp/']) // here it works as well
+
+ // exec(["-c","find","/tmp/"]) // does not work I guess is normal
+}
diff --git a/v_windows/v/old/examples/process/process_script.v b/v_windows/v/old/examples/process/process_script.v
new file mode 100644
index 0000000..fa415e7
--- /dev/null
+++ b/v_windows/v/old/examples/process/process_script.v
@@ -0,0 +1,59 @@
+module main
+
+import os
+
+// a test where we execute a bash script but work around where we put script in bash inside bash
+
+fn exec(path string, redirect bool) {
+ mut line := ''
+ mut line_err := ''
+ mut cmd := os.new_process('/bin/bash')
+
+ if redirect {
+ cmd.set_args(['-c', '/bin/bash /tmp/test.sh 2>&1'])
+ } else {
+ cmd.set_args([path])
+ }
+
+ cmd.set_redirect_stdio()
+ cmd.run()
+ if cmd.is_alive() {
+ for {
+ line = cmd.stdout_read()
+ println('STDOUT: $line')
+
+ if !redirect {
+ line_err = cmd.stderr_read()
+ println('STDERR: $line_err')
+ }
+
+ if !cmd.is_alive() {
+ break
+ }
+ }
+ }
+ if cmd.code > 0 {
+ println('ERROR:')
+ println(cmd)
+ // println(cmd.stderr_read())
+ }
+}
+
+fn main() {
+ script := '
+echo line 1
+#will use some stderr now
+echo redirect 1 to 2 1>&2
+echo line 3
+'
+
+ os.write_file('/tmp/test.sh', script) or { panic(err) }
+ // os.chmod("/tmp/test.sh",0o700) //make executable
+
+ // this will work because stderr/stdout are smaller than 4096 chars, once larger there can be deadlocks
+ // in other words this can never work reliably without being able to check if there is data on stderr or stdout
+ exec('/tmp/test.sh', false)
+
+ // this will always work
+ exec('/tmp/test.sh', true)
+}
diff --git a/v_windows/v/old/examples/process/process_stdin_trick.v b/v_windows/v/old/examples/process/process_stdin_trick.v
new file mode 100644
index 0000000..7a1455d
--- /dev/null
+++ b/v_windows/v/old/examples/process/process_stdin_trick.v
@@ -0,0 +1,83 @@
+module main
+
+import os
+
+// this is a example script to show you stdin can be used and keep a process open
+
+fn exec(cmd string) (string, int) {
+ mut cmd2 := cmd
+ mut out := ''
+ mut line := ''
+ mut rc := 0
+ mut p := os.new_process('/bin/bash')
+
+ // there are methods missing to know if stderr/stdout has data as such its better to redirect bot on same FD
+ // not so nice trick to run bash in bash and redirect stderr, maybe someone has a better solution
+ p.set_args(['-c', 'bash 2>&1'])
+ p.set_redirect_stdio()
+ p.run()
+
+ if !cmd2.ends_with('\n') {
+ cmd2 += '\n'
+ }
+
+ p.stdin_write(cmd2)
+ p.stdin_write('\necho **OK**\n')
+
+ for {
+ if !p.is_alive() {
+ break
+ }
+ line = p.stdout_read()
+ println(line)
+ // line_err = p.stderr_read() //IF WE CALL STDERR_READ will block
+ // we need a mechanism which allows us to check if stderr/stdout has data or it should never block
+ // is not a good way, need to use a string buffer, is slow like this
+ out += line
+ if out.ends_with('**OK**\n') {
+ out = out[0..(out.len - 7)]
+ break
+ }
+ }
+
+ // println("read from stdout, should not block")
+ // is not really needed but good test to see behaviour
+ // out += p.stdout_read()
+ // println("read done")
+
+ // println(cmd.stderr_read())
+
+ if p.code > 0 {
+ rc = 1
+ println('ERROR:')
+ println(cmd2)
+ print(out)
+ }
+ // documentation says we need to call p.wait(), but this does not seem to work, will be process stop or become zombie?
+ // p.wait()
+
+ return out, rc
+}
+
+fn main() {
+ mut out := ''
+ mut rc := 0
+
+ // the following does not work, not sure why not
+ // out,rc = exec("find /tmp/ && echo '******'")
+
+ out, rc = exec("find /tmp/ ; echo '******'")
+ println(out)
+ assert out.ends_with('******\n')
+
+ out, rc = exec('echo to stdout')
+ assert out.contains('to stdout')
+
+ out, rc = exec('echo to stderr 1>&2')
+ assert out.contains('to stderr')
+
+ out, rc = exec('ls /sssss')
+ assert rc > 0 // THIS STILL GIVES AN ERROR !
+
+ println('test ok stderr & stdout is indeed redirected')
+}
--
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